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US4827353A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of and circuit arrangement for changing the resolution of binary pseudo-halftone pictures

Assignee: US Philips Corp
•
Filing: 1986-12-19
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Granted: 1989-05-02
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Expires: 2006-12-19
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Abstract

Abstract A first pseudo-halftone picture is converted to a second pseudo-halftone picture of reduced resolution in the ration m:n by dividing the first picture into contiguous picture fields each having i·n lines and j·n columns of picture elements in contiguous square subfields each having n 2 picture elements. m 2 elements are selected from each subfield in accordance with a selection sequence which depends on the position of the subfield in the picture field, the elements being selected from all i·n lines and all j·n columns of each picture field, the selection sequence being the same for each picture field.

Inventors

  • 👤 Bernd Ehlers
  • 👤 Gerhard Renelt

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 15:22
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40075; H04N1/40068

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 180 words
A method of converting a first pseudo-halftone picture into a second pseudo-halftone picture of reduced resolution such that n 2 picture elements of the first picture correspond to m 2 picture elements of the second picture where m<n, said first pseudo-halftone picture being formed by a first matrix of binary picture elements whose values are determined in accordance with an ordered dither method, said converting method comprising the steps of dividing the first pseudo-halftone picture into contiguous picture fields each having i·n lines and j·n columns of picture elements, said picture elements being arranged in contiguous square subfields, each subfield having n 2 picture elements, selecting m 2 picture elements from each subfield in accordance with a selection sequence which depends on the position of the subfield in the corresponding picture field, said picture elements being selected from all i·n lines and all j·n columns of the corresponding picture field, said selection sequence being the same for each picture field, and generating said second pseudo-halftone picture from the picture elements selected from each picture field of the first pseudo-halftone picture.
Claim 2
Independent Claim 180 words
A method of converting a first pseudo-halftone picture into a second pseudo-halftone picture of reduced resolution such that n 2 picture elements of the first picture correspond to m 2 picture elements of the second picture where m<n, said first pseudo-halftone picture being formed by a first matrix of binary picture elements whose values are determined in accordance with an ordered dither method, said converting method comprising the steps of dividing the first pseudo-halftone picture into contiguous picture fields each having i·n lines and j·n columns of picture elements, said picture elements being arranged in contiguous square subfields, each subfield having n 2 picture elements, selecting m 2 picture elements from each subfield in accordance with a selection sequence which depends on the position of the subfield in the corresponding picture field, said picture elements being selected from all i·n lines and all j·n columns of the corresponding picture field, said selection sequence being the same for each picture field, and generating said second pseudo-halftone picture from the picture elements selected from each picture field of the first pseudo-halftone picture.
Claim 3
Dependent Claim 66 words
A method as in claim 1 wherein said second pseudo-halftone picture is generated by arranging the selected picture elements in a second matrix, the position of each m 2 elements in teh second matrix basically corresponding to the position of the respective subfield in the first matrix of the first pseudo-halftone picture, whereby the optical impression of the first picture is maintained in the second picture.

References Cited (Backward Citations)

JPS58161588A Cited
US4698778A Cited
US4701808A Cited
JPS60142670A Cited
JPS60142669A Cited
JPS60223377A Cited
US4740844A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-05-01 1992-10-31 1993-05-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-05-01 1996-10-31 1997-05-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-05-01 2000-10-31 2001-05-02 $7700.00 Window Closed / Lapsed

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